Note: This feature is part of a staggered rollout, so not every account (Pro & Enterprise) has it yet. If you haven’t seen it in your account yet, it should appear in the next few days.
Energy arbitrage (included for Pro and Enterprise users) is a battery dispatch strategy that charges a battery energy storage system from the grid or on-site generation when electricity prices are low and discharges it when prices are high, capturing the price difference as a financial return. Because many utility tariffs, particularly time-of-use (TOU) and real-time pricing structures, charge different rates for energy depending on the hour of the day, shifting consumption from expensive periods to inexpensive ones directly reduces the energy charge portion of the utility bill. The value of this strategy depends on the spread between peak and off-peak rates and the battery's round-trip efficiency, since some energy is lost with each charge-discharge cycle.
Energy Arbitrage Simulations
To model Energy Arbitrage in HelioScope, on the Storage tab, enter your battery specs
On the right-hand side, you can toggle the Storage Simulation on and off
Energy Arbitrage Configuration
Select Energy Arbitrage as your storage configuration
Charging/discharging behavior:
Grid charging
Grid charging allows the battery to charge from the utility grid in addition to on-site PV generation. This lets the system store low-cost grid energy for later use. The battery can only discharge to on-site loads, not export to the grid.
Grid discharging
Grid discharging allows the battery to export stored energy back to the grid, while restricting charging to PV generation only. This ensures the energy exported from the battery is solar-sourced rather than purchased from the utility, which can be useful where interconnection rules, incentive programs, or export compensation structures require or favor battery exports to be PV-charged.
Grid charging + discharging
Grid charging + discharging gives the battery full two-way interaction with the grid: it can charge from both the grid and PV, and discharge to on-site loads or export to the grid. This is the most flexible option and is typically required to capture the full value of energy arbitrage, since the battery can buy energy when prices are low and sell or use it when prices are high.
Financial Configuration
You can select the Financial Configuration for your project. For instructions on how to create a Financial Model, click here.
Consumption
You can upload a consumption file (recommended 15 min interval data upload for accuracy). Or you can enter monthly consumption values (For US-based projects, the default consumption data is sourced from NREL. Typical data is used from a nearby location and a residential base building type, pro-rated to 1,500 kWh monthly. Edit this or upload your own for more accurate storage simulation results)
Utility Rate
Select the utility rate that will be used for the storage simulation. For accurate simulation results, verify the rate includes all relevant charges, including energy and demand.
Export Limit
This input allows you to set the export limit in kW (a kW export limit caps the net AC power flowing through the point of interconnection (POI) to the grid)
Running the simulation: To run the simulation, click "Calculate energy arbitrage"
Once the simulation has been completed, you can see the Energy arbitrage calculations
- Storage annual savings: the estimated yearly bill savings from Energy Arbitrage, based on the rate or tariff the simulation used.
- Annual throughput: the total energy cycled through the battery in a year (usually kWh or MWh).
Note: If you do not see the storage simulation panel, reload your page or open HelioScope in a new tab